As women and their supporters marched in Washington and cities around the world Saturday, Sen. Ben Cardin joined with SenateDemocrats to reintroduce the Equal Rights Amendment.

“Many Americans would be shocked to find out that the U.S. Constitution still lacks a provision ensuring gender equality,” the Maryland Democrat said in a statement. “Think about that: in 2017, women lack the same constitutional protections as men. This is clearly wrong and needs permanent correction.”

In a separate effort earlier this week, Cardin introduced legislation to extend the deadline for the states to ratify the 1972 Equal Rights Amendment.

The original effort fell three states short of the three quarters needed for passage by the 1979 deadline. An extension to 1982 yielded no more states.

On Saturday, Cardin joined Sen. Bob Menendez of New Jersey in reintroducing the amendment. Co-sponsoring were Sens. Cory Booker of New Jersey, Sherrod Brown of Ohio, Chris Coons of Delaware, Dianne Feinstein of California, Kirsten Gillibrand of New York and Ed Markey of Massachusetts in reintroducing the constitutional amendment first proposed in 1923.

The 28th amendment would guarantee that “equality of rights under the law shall not be denied or abridged by the United States or by any State on account of sex.”

Congress approved the amendment in 1972 and set a seven-year deadline for ratification.

In an early battle of the modern-day culture wars, opponents argued that the amendment would upset traditional gender roles, and subject women to the military draft.

Thirty-five states, including Maryland, ratified the amendment, short of the thirty-eight required for passage. Attempts in recent years to revive it – by reintroducing it, or extending the deadline – have been unsuccessful.

Photos from the Women's March on Washington and a companion march in Baltimore on Saturday.

“America was built on the promise of equal rights,” Cardin said. “It’s long past time for us to recognize the equality of women in the foundational document of our nation.”

Maryland added language similar to the Equal Rights Amendment to the Declaration of Rights in the state constitution in 1972: “Equality of rights under the law shall not be abridged or denied because of sex.”